Options for a Fan Switch without a Neutral?

Fan wiring is a whole separate issue, and can get very complicated. I’m not an electrician, and I leave discussions of specific wiring mappings to the experts. but if you already have a remote, you might be able to just use a bond remote with it and get smartthings integration that way.

See the community FAQ for various options. It says Alexa in the thread title, but it applies whether you use a voice assistant or not.

FAQ: 2020 Ceiling Fan and Dimmer light wall mount control compatible with SmartThings and Alexa?

(Also, by the way, you can’t use any kind of device intended just for lighting control for a fan motor. The physics are different and you will burn out either the switch or the fan. So you need to choose a device which is specifically spec’d for motor control. Or, like the bond does, use an alternative remote.)